bump(github.com/benbjohnson/go-raft): d46748244f1f1830a002b8f645342426c5d73e81

third_party/github.com/benbjohnson/go-raft/snapshot.go

@@ -0,0 +1,65 @@
+package raft
+
+import (
+	//"bytes"
+	"encoding/json"
+	"fmt"
+	"hash/crc32"
+	"os"
+	"syscall"
+)
+
+//------------------------------------------------------------------------------
+//
+// Typedefs
+//
+//------------------------------------------------------------------------------
+
+// the in memory SnapShot struct
+// TODO add cluster configuration
+type Snapshot struct {
+	LastIndex uint64 `json:"lastIndex"`
+	LastTerm  uint64 `json:"lastTerm"`
+	// cluster configuration.
+	Peers []string `json: "peers"`
+	State []byte   `json: "state"`
+	Path  string   `json: "path"`
+}
+
+// Save the snapshot to a file
+func (ss *Snapshot) save() error {
+	// Write machine state to temporary buffer.
+
+	// open file
+	file, err := os.OpenFile(ss.Path, os.O_CREATE|os.O_WRONLY, 0600)
+
+	if err != nil {
+		return err
+	}
+
+	defer file.Close()
+
+	b, err := json.Marshal(ss)
+
+	// Generate checksum.
+	checksum := crc32.ChecksumIEEE(b)
+
+	// Write snapshot with checksum.
+	if _, err = fmt.Fprintf(file, "%08x\n", checksum); err != nil {
+		return err
+	}
+
+	if _, err = file.Write(b); err != nil {
+		return err
+	}
+
+	// force the change writting to disk
+	syscall.Fsync(int(file.Fd()))
+	return err
+}
+
+// remove the file of the snapshot
+func (ss *Snapshot) remove() error {
+	err := os.Remove(ss.Path)
+	return err
+}